On Tue, 3 Apr 2007, temiz wrote:> hello > > how can I confine a dataframe with a known polygon that is part of whole > data ?Could I suggest following up this question on the R-sig-geo list? It is not clear what you want to do - are the rows in the data frame points which may lie inside or outside a polygon? If so, the overlay() methods in the sp package may be suitable.> > regards > >-- Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: Roger.Bivand at nhh.no
hello
how can I confine a dataframe with a known polygon that is part of whole
data ?
regards
--
Ahmet Temiz
--
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Roger Bivand wrote:> On Tue, 3 Apr 2007, temiz wrote: > > >> hello >> >> how can I confine a dataframe with a known polygon that is part of whole >> data ? >> > > Could I suggest following up this question on the R-sig-geo list? It is > not clear what you want to do - are the rows in the data frame points > which may lie inside or outside a polygon? If so, the overlay() methods in > the sp package may be suitable. > > >> regards >> >> >> > >thank you for your reply I have not been aware of that list (R-sig-geo list) My data is elevation point data in a text file. I want to create DEMs with different interpolation methods for comparision. Actually I created DEM in GRASS using spline tension. Then I want to create DEM in R with different techniques to compare. But my data seems so huge for GSTAT-kriging and FIELDS-krig. So I decided to select smaller interpolation area within whole data. How can I define a subregion in which I do interpolation ? I found locator and chull function that may serve this. I will regard your recommendations. PS : Thinking facing a memory problem, I refrained from GRASS-R interface. -- Ahmet Temiz -- This message has been scanned for viruses and\ dangerous con...{{dropped}}